Heat butter or margarine in skillet. Add onion, green pepper, and base. Sauté one minute. Add ham, black and red beans, mustard, and black pepper. Sauté until heated thoroughly. Divide between the pita pockets and add a little western style dressing for that extra kick.
Food for Thought
Other ideas for leftover diced ham. Add to scalloped potatoes, to a rice pilaf, to soups like a Corn Chowder or a Navy Bean Soup.